This document discusses the risks of vaginal birth after cesarean (VBAC) to patients, providers, and the public. It provides a history of VBAC rates in the US from the 1970s-2000s as standards of care shifted. While VBAC can have benefits like lower morbidity rates, it also carries risks like uterine rupture. The document examines evidence on risks and benefits but notes limitations. It concludes that VBAC decisions require balancing risks while supporting informed patient choice when possible.

1. Vaginal Birth After Cesarean Section
Risk to Patient, Provider and Public
Devon M. Fagel, J.D.
OBGYN Clerkship
May 19, 2011

2. Learning Objectives
• Understand the historic epidemiology of VBAC
• Identify both the medical risks and benefits of VBAC
• Explain the financial incentives for encouraging VBAC
• Describe the legal risks to physician and hospital
facility
• Discuss the risks of overindulging patient autonomy
• Conclude with an example of VBAC complications

3. History & Epidemiology
• 1916: “Once a cesarean, always a cesarean”
• 1970: Rate of cesarean section at 5.5%
• 1978: Due to increase diagnosis of dystocia and concurrent rise
in med-mal litigation, rate of C-sections dramatically increases
• 1980: NIH begins to encourage trial of labor (TOL) for VBAC.
• 1981: Rate of VBAC at 3.5%.
• 1988: Rate of C-section at 24.7%
• 1990: HHS proposes 15% goal for total C-sections which
incorporated a 35% goal for VBAC.
Cochrane Database Syst Rev. 2004 Oct 18; (4)
Shifting Standards of Care

4. History & Epidemiology
• 1991: Rosen et al. found no significant difference in maternal
mortality rate for elective repeat C-section (ERCS) vs. TOL.
• 1994: Flamm et al. reported TOL resulted in decreased rates
of postpartum transfusions/fevers and shorter hospitalizations.
• 1997: Hook et al. reported infants born after TOL developed
fewer neonatal respiratory problems compared with ERCS.
• 1990’s: Insurance companies and managed care organizations
began to mandate that all women (except when
contraindicated) must undergo a trial of labor.
• 1996: Rate of VBAC reached 28.3%, total C-section at 20.7%.
Cochrane Database Syst Rev. 2004 Oct 18; (4)
Shifting Standards of Care

6. History & Epidemiology
• 1999: NEJM editorial questioned safety of push for VBAC,
reporting increasing rates of uterine rupture throughout 90’s.
• 1999: Several journals reported use of Misoprostol (which
induces uterine contractions and ripening) resulted in 30-fold
increase in uterine rupture compared to spontaneous labor.
• 2004: Cochrane review concluded, ERCS and VBAC are both
“associated with benefits and harms.” Evidence drawn from
non-randomized studies and thus present bias. “Any results
must be interpreted with caution.”
• 2004: ACOG - “Because uterine rupture may be catastrophic,
VBAC should be attempted in institutions equipped to respond to
emergencies with physicians immediately available to provide
care.ACOG Practice Bulletin #54, July 2004
Shifting Standards of Care

7. • NIH admitted “general paucity of high-
level evidence about both medical and
non-medical factors, which prevents the
precise quantification of risks and benefits
that may help to make an informed
decision about TOL vs ERCS.
• Panel’s “major goal to support pregnant
women with one prior transverse uterine
incision make an informed decision... and
whenever possible, the woman’s
preference should be honored.”
• Panel is “concerned about the barriers to
clinicians and facilities that are able and
willing to offer TOL... and recommends
ACOG and ASG reassess requirement...
for immediately available surgical and
anesthesia personnel.”
• Panel is “concerned that medical-legal
considerations exacerbate these barriers.”
NIH Consensus Statement, Volume 27, Number 3, March 8-10, 2010

8. Benefits of VBAC
• Lower rates of maternal morbidity including decreased
postpartum fever, wound infection, blood transfusion,
maternal discomfort, hysterectomy and length of stay
• Lower rates of neonatal respiratory distress

9. Risks of VBAC
• Increased rates of uterine rupture (0.2% to 9% depending on
risks)
• Increased rates of perinatal death (.3% for ERCS vs .6% for
TOL)
• Though inductions agents are generally contraindicated as
studies have shown 5-30 fold increase in rates of uterine rupture,
these agents continue to be used in VBACs.
• Additional risk factors include:
• Maternal age > 30
• Fetal weight > 4000g
• No hx of vaginal delivery
• Type of previous C-section
• Classical incision (4-9%)
• T-shaped incision (4-9%)

10. The Problem with Patient Autonomy
• ACOG approved VBAC candidates
• Ability to perform emergency C-section
• No hx of previous uterine rupture
• Maximum of 2 previous CS
• Clinically adequate pelvis
• Vertex fetal presentation
• No other uterine scars
• Clinically adequate

11. The Problem with Patient Autonomy
• Ability to perform emergency C-section
• Contraindicated with classical incision
• Maximum of 2 previous CS

12. The Problem with Patient Autonomy